Planets usually move across our night sky from west to east relative to the background stars. This steady motion is a result of their orbits around the Sun. But every so often, a planet like Mars appears to hit the brakes, reverse direction, and move backward - a puzzling motion known as retrograde. This animation breaks down the mystery behind retrograde motion, focusing specifically on Mars. You'll see how the motion of Earth and Mars in their respective orbits creates the illusion of Mars loo

Why Mars Moves Backward - This is the retrograde motion of Mars. So why does Mars sometimes appear to move backward in the night sky? Retrograde motion is an optical illusion that happens when Earth, moving faster in its orbit, overtakes Mars. As we pass it, Mars appears to slow down, stop, and move westward temporarily — even though it's still moving forward in space. Because Mars orbits farther from the Sun than Earth does, it takes longer to complete one orbit. When Earth "laps" Mars about ev

Jupiter and Saturn go retrograde 🪐 This video explains the apparent retrograde motion of the outer planets using Jupiter and Saturn as examples. Saturn goes retrograde for about 4.5 months every year. Jupiter also moves “backwards” for approximately 4 months annually. 📖 Retrograde motion is an optical illusion caused by differences in the planets’ orbital speeds. When a planet seems to reverse its direction in the sky, it’s called retrograde motion (from the Latin word retrogradus – "going bac

Mercury’s retrograde motion This video explains Mercury’s apparent retrograde motion in our skies: the inner planet appears to retrace its steps a few times per year. Every planet does this, every year. Retrograde motion is an optical illusion caused by differences in the planets’ orbital speeds. When a planet seems to reverse its direction in the sky, it’s called retrograde motion (from the Latin word retrogradus – "going backward"). Courtesy: Star Walk Based on video by James O'Donoghue / NASA